Move settings only relevant to the parent group into an "Administration" menu

What does this MR do?

See #209020 (closed)

This MR is related to Group Managed Accounts (&2777 (closed)). The general idea of this MR is to move settings that are only relevant to the parent group into their own menu ("Administration").

Changes:

• Moves "SAML SSO", "Usage Quotas", and "Billing" from the "Settings" menu to a new "Administration" menu. This menu is only visible to group owners and not visible from a subgroup.
• Removes "Restrict access by IP address" and "Restrict membership by email" from subgroup settings as they can only be changed from the parent group.

Local Development

Testing this feature requires the following:

• An EE license. See https://about.gitlab.com/handbook/developer-onboarding/#working-on-gitlab-ee.
• The following feature flags enabled. group_saml, enforced_sso, enforced_sso_requires_session, group_managed_accounts, sign_up_on_sso, convert_user_to_group_managed_accounts.
• group_saml enabled in config/gitlab.yml. See https://gitlab.com/gitlab-org/gitlab-development-kit/-/blob/master/doc/howto/saml.md#gitlab-configuration. Note: Ensure this is added to the development: section of your config

Screenshots

Expand

Page	Before	After
Parent Group
Subgroup Settings

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• [-] Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• [-] Security reports checked/validated by a reviewer from the AppSec team